Antidiarrhoeal activity of eriosematin E isolated from the roots of Eriosema chinense Vogel

Background: Roots of the plant Eriosema chinense Vogel (Fabaceae) is distributed mainly over the Eastern Himalayan region of India and China. The roots of the plant are used as a vegetable by the people of Northern Australia, China and North East India and are used traditionally by the tribal people of Meghalaya (India) for the treatment of diarrhoea. It has been reported to have significant antidiarrhoeal, cytotoxic and antimycobacterial activity. Purpose/Objective: The present investigation was undertaken to isolate a lead molecule responsible for the observed antidiarrhoeal activity. Methods: Eriosematin E, a prenylated flavanone, was isolated using column chromatography and was characterized by comparing its melting point and spectroscopic data (UV, IR, H-1 NMR, C-13 NMR, Mass Spectra) from literature. Eriosematin E (2.5, 5 and 10 mg/kg p.o.) was then screened for normal faecal excretion rate and castor oil-induced diarrhoea models in rats. Further, it was examined for small intestinal transit, intestinal fluid accumulation and PGE(2) induced enteropooling models in rats. Biochemical estimations and Na+ and K+ concentration in intestinal fluid were also determined along with colonic histopathological studies. Results: The results illustrated a significant (P < 0.05) reduction in normal faecal output at 10 mg/kg p.o. after 5th and 7th h of treatment and also showed maximum protection of 69.43% from diarrhoea in the castor oil-induced diarrhoea model. Significant results were also observed at the maximum effective dose of eriosematin E (10 mg/kg p.o.) in inhibiting peristaltic index (small intestinal transit) and reducing intestinal fluid volume of castor oil induced and PGE(2) induced enteropooling models. Further, eriosematin E restored all the alterations in biochemical parameters such as nitric oxide, protein, DNA, superoxide dismutase, catalase and lipid peroxidation. It also significantly recovered Na+ and K+ loss from body and confirmed its protective nature through the histopathological studies. Conclusion: The study corroborates the antidiarrhoeal potential of eriosematin E which may be attributed to its antisecretory and antioxidant potential. (C) 2016 Elsevier GmbH. All rights reserved.